ROLLN

i have had a slight miss for as long as i can remeber, i decided to scan it today with my buddies genisis. i know right now i have a code coming up for the cat(p0420). but when we scanned it while it was running, it was telling me that there were about 13 misfires per scan cycle. primarliy cylinder 3,4, and couple in cylinder 1. would the cat code effect this. i had this miss before that cat code ever came up. the car runs and drives everywhere, and it wont die out. it just has a slight miss every couple seconds. is this natural? by the way, i am not throwing any other codes besides the p0420 code. any ideas what to look for. the car has stock everything, it used to have a small dry kit on it. any help on this would really be great.

edit, just scanned it again after wire change, car feels better but still has the miss. when scanning,it reads current cylinder misfires 1,2,3,4,5,6,7,8, ect. some cylinders still have a misfire at idle. they go away if you hold the throttle up. basiclly i get a couple misfires on a few different cylinders, its never the same one though. it is not throwing any codes what so ever for a misfire, just the p0420 code. any ideas what this could be???
a/f was 14.3
spark was bewtween 16-20 degrees, occasionally jumping to 22.




btw, the misfire count would go to zero when given gas.

2001NBMZ28

P0420 is the drivers side cat, you're getting misfires on both banks so I'd look at the plugs/wires if they've been in a while. If you have a 00-02 and less than 120K have the dealer replace that cat for you free.

ROLLN

i was gonna put longtubes on next month with no cats, so i dont want to bring it to the dealer, i am doing the plugs and wires now, so hopefully thats all it is.